2-Mercaptobenzothiazole, also known as Accelerator M or Accelerator MBT, and further called as “quick heating powder,” is a general-purpose rubber vulcanization accelerator. It has the characteristics of fast vulcanization acceleration action, low vulcanization flatness, no early vulcanization during mixing and the like, and is widely applied to the rubber processing industry.
There are many synthesis methods for 2-mercaptobenzothiazole, and according to the raw materials, may be divided into an o-nitrochlorobenzene method, an aniline method, a mixed nitrobenzene and aniline method, a nitrobenzene method, a nitroso-benzene method, etc. The o-nitrochlorobenzene method, the aniline method, and the mixed nitrobenzene and aniline method are more frequently used. However, when the o-nitrochlorobenzene method is used for producing 2-mercaptobenzothiazole, the cost of the raw materials is high and the production process is complex, so that it is unsuitable for industrial application. The mixed nitrobenzene and aniline method is low in production cost and may reduce H2S produced by reaction by ⅓ of the aniline method, but it has the problems of difficulties in control of the reaction and high requirements on material of reactor, so currently, the method is less frequently used in China. Therefore, the aniline method for synthesizing 2-mercaptobenzothiazole is the method that has been generally adopted by each manufacturer for the agent.
The aniline method for producing 2-mercaptobenzothiazole has the characteristics of stable raw material sources, low difficulties in operation, and low requirements for the quality of the reactor. However, it still has the shortcomings of relatively low purity of the product, high amount of tar, relatively low yield, etc.